Announcement

After 5 years serving the vintage Apple enthusiast community, ThinkClassic has been marked for closure and is now in caretaker mode. Please see this thread for further information. Please direct any questions, comments and enquiries about the website, management and ownership to this thread.

Lisa 400k floppy emulation with Floppy Emu

I'm not a Lisa guy, and not really interested in becoming one, but I've become curious just how close or far the Floppy Emu is from working on the Lisa. Here's what I think I know - please correct me where I'm wrong.

Lisa 1 had the Twiggy drives. And not many people own one of these.Lisa 2, later renamed Macintosh XL, had the same Sony 400k floppy mechanism as the Mac 128K. And the same DB-19 external floppy port.Lisa 2 used a different filesystem than the Mac (MFS). So even though they used the same drive and media, the disks weren't interchangeable.Lisa software called Macworks XL allows a Lisa 2 to read 400k MFS macintosh floppies.

If that's all true, someone with a Lisa 2 and Floppy Emu should be able to run Macworks XL, then use a Floppy Emu to load a Mac disk on the Lisa. Anyone want to try it?

More interesting, it means that if we knew all the details of the Lisa filesystem, it would theoretically be possible to use the Floppy Emu hardware to emulate native Lisa floppies. For sure the Emu firmware would need to be modified to support the 12 tag bytes per sector that the Lisa requires, but I'm guessing there's a lot more to it than that. Size of a sector, number of sectors per track, sector ordering, sector headers, sector footers, sector checksums, etc… all may be different from a Mac. And do Lisa floppies even use GCR encoding? Who knows.

I also saw something about later Lisas that could use 800k floppies, but I'm not sure if that's right.

Re: Lisa 400k floppy emulation with Floppy Emu

There was a Facebook discussion that touched on Lisa floppy emulation. OK, so no external floppy port then. But it should work when connected to the internal floppy port, with a regular IDC-20 ribbon cable?

Also in the same Facebook discussion was someone asking how Floppy Emu was different from $30 floppy emulators on Amazon. A fair question, even if he phrased it rather aggressively. But that wasn't the same person who was asking about the Lisa.

Re: Lisa 400k floppy emulation with Floppy Emu

i don't like it when people bitch about the price of stuff for LISA… THEN DONT COLLECT LISA………………….my god.. people go to all the trouble to make these gadgets and are trying to break even with the cost of the project and their time…http://www.ebay.com/itm/Profile-Widget- … 2ed04dc191

i mean the lisa market is narrow as helllllllll… anyways. The guy was nice enough to make it, stop trying to find ways around paying whatthe thing is worth.

Re: Lisa 400k floppy emulation with Floppy Emu

I have no idea what Facebook page everyone is ranting about. Do I want to?

bigmessowires wrote:

For sure the Emu firmware would need to be modified to support the 12 tag bytes per sector that the Lisa requires, but I'm guessing there's a lot more to it than that. Size of a sector, number of sectors per track, sector ordering, sector headers, sector footers, sector checksums, etc… all may be different from a Mac. And do Lisa floppies even use GCR encoding? Who knows.

Lisas are GCR, 512 byte sectors... basically compatible with the Mac disk geometry, there's just that 12 byte of tag data to worry about. Several programs exist to read and write Lisa disks on Macs; supposedly old versions of DiskCopy can do it, as well as something called "DART".